One of my most frustrating issues with Sketchup is with one of the simplest of tasks on the most basic drawing level. Simple lines. If I draw a line, and then I draw another line that is an extension of that line, Sketchup forms two separate lines. That’s OK. But usually, I want those two lines to become one. Leaving two lines often leaves an unwanted intersection that complicates the drawing unnecessarily. I can’t believe there is no way to “join” or “weld” those two lines together.
The most simple and logical way to have this work, in my opinion, would be that if I have two in-line lines, with no other object at that intersection, and I re-draw a whole line the length of those two lines, that action should immediately turn those two lines into one line. I’m amazed that this does not work this way now. I can not think of any reason why this should not be implemented.